JPH08174049A - Production of superplastically molded goods - Google Patents

Abstract

PURPOSE: To rapidly and easily produce final molded goods by one stage of process with a good productivity by controlling the heating temp. to be applied on the blank of a supply section by the temp. at which the blank exhibits superelasticity and the temp. rise by the heat of working generated at the time when the blank is extruded from the supply section to a passage section. CONSTITUTION: The blank 7 of a superplastic material is first loaded into the supply section 2 of a die 1 and is heated by a heating means 6 up to the heating temp. attained after the temp. rising-component by the heat of working is subtracted from the temp. at which the blank exhibits the superelasticity. The blank is pressurized at one time by means of a punch 5 arranged right above the supply section 2 when the heating temp. is attained. The blank 7 is extruded and compressed through the passage section 3 to a molding section 4 and is rapidly heated by the heat generated by pressurization up to the temp. at which the blank exhibits the superelasticity. In succession, the blank is rapidly cooled by a temp. difference between the molding section 4 and the die 1 and is molded and solidified to a desired shape. Then, the time at which the blank is exposed to the high temp. is short and, therefore, the change in the structure of the molded goods and the consequent degradation in the properties are minimized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a superplastically molded product utilizing heat generated by processing.

[0002]

2. Description of the Related Art Conventionally, as a method of manufacturing a molded product such as a rapidly solidified material (fine crystalline alloy material) that exhibits superplasticity, the heating temperature during processing is increased, and the processing time at high temperature is long. In order to avoid aging, the processing is done slowly or the material is molded in several steps from preforming to finish forming to produce the final molded product. However, the problems in the series of processing steps as described above are that it takes a long time overall, a large processing and forming force is required, and several steps from preforming to finish forming are required. For example, the number of molds for processing increases. That is, since the work-forming force is proportional to the pressure receiving area of the material, it cannot be formed in one step, and it is necessary to gradually form it in several steps from preforming to finish forming. As a result, the material is exposed to high temperature for a long time, resulting in problems such as coarsening of crystal grain size and deterioration of physical properties. In addition, when slowly forming in one mold, the material is placed in the mold and heating is performed from the outside (from the mold) by induction heating, contact heating, and electric heating. Becomes longer, leading to coarsening of the above-mentioned crystal grain size and deterioration of physical properties, and the mold itself has a temperature almost the same as or slightly higher than that of the material, so that the molded product after cooling can be cooled smoothly. There is a problem that it cannot be done.

On the other hand, as a method of manufacturing a molded product made of a rapidly solidified material in consideration of the heat generated by processing caused by plastic working, a manufacturing method described in JP-A-3-247706 is known. This publication discloses that plastic working is performed in the presence of an endothermic material that absorbs the working heat generated in the material by plastic working in order to suppress the temperature rise of the material due to working heat. However, even in the above-mentioned method for producing a molded product, there is a problem that the exposure time at a high temperature becomes long, coarsening of the crystal grain size and deterioration of physical properties are caused similarly to the above, and it is contained in the material or arranged around it. It is difficult to control or set the amount of heat absorbing material added, the relative relationship with the material, etc. Also, when processing is performed by including the heat absorbing material in the material, the molded product contains the heat absorbing material. Therefore, there is also a problem that the physical properties are deteriorated.

[0004]

Therefore, according to the present invention, the heating temperature is controlled by positively utilizing the temperature rise due to the processing heat generated during the molding process, and the final molded product is processed by one step. An object of the present invention is to provide a method for producing a molded product which can be easily produced with high productivity in a short time and which can maintain excellent properties of the final molded product as a rapidly solidified material.

[0005]

In order to achieve the above-mentioned object, according to the present invention, a supply part to which a material is supplied, a forming part for forming the material into a desired shape, and the supply part and a forming part. The material having superplasticity is loaded in the supply part of the mold having the passage part communicating with the part, and the material is supplied to the forming part through the passage part and compressed to perform the forming process. A method for manufacturing a superplastically formed product, wherein the heating temperature (T ₁ ) applied to the material of the supply section is a temperature at which the material exhibits superplasticity (T ₂ ) and the material is extruded from the supply section into the passage section and deformed. There is provided a method for producing a superplastically formed product, which is controlled by the temperature rise (ΔT) due to the heat generated during processing. In a preferred embodiment, the temperature rise (ΔT) due to the above-mentioned heat generation of processing is obtained from the following equations (1) and (2), and the heating temperature (T ₁ ) is T ₁ = T ₂ −Δ
It is set by T, and more preferably, the heating temperature (T ₁ ) is the crystal coarsening start temperature (T _x of the material showing superplasticity).
) Perform the molding process by controlling it so that it becomes lower.

[0006]

[Equation 2]

[0007]

According to the method disclosed in the above-mentioned Japanese Patent Laid-Open No. 3-247706, the processing heat generated in the material by the plastic working is efficiently absorbed by, for example, the heat absorbing material arranged around the material, and the working heat is generated. It suppresses the temperature rise of the material, and in this case, the processing heat is not used for plastic working of the material, so a large waste is generated in terms of thermal efficiency,
Also, the high temperature exposure time becomes longer. On the other hand, the method of the present invention positively utilizes the temperature rise due to heat generation during processing for forming the raw material, and attempts to perform the forming with high productivity in a short time in one step. That is, in the method for producing a superplastically molded product of the present invention, the heating temperature (T ₁ ) applied to the material of the feeding part is the temperature at which the material exhibits superplasticity (T ₂ ) It is characterized in that it is controlled by the temperature rise (ΔT) due to the heat generated by processing when it is extruded and deformed. More specifically, the temperature rise (ΔT) due to the above-mentioned heat generation of processing is obtained from the above equations (1) and (2), and the heating temperature (T ₁ ) is set by T ₁ = T ₂ −ΔT.

Temperature rise due to heat generated by processing of material (ΔT)
Is calculated by the equation (2). By setting the strain rate, the stress σ is obtained from the equation (1), and by substituting this into the equation (2), the temperature rise (ΔT) can be calculated. The temperature range in which the material used for processing exhibits superplasticity is known by measuring in advance, and an appropriate temperature within the temperature range is set as the temperature (T ₂ ) exhibiting superplasticity. The temperature obtained by subtracting the increase (ΔT) due to heat generation from processing from the temperature (T ₂ ) showing this superplasticity is set as the heating temperature (T ₁ ), and the material is in a structurally stable temperature range by the external heating means. Heat to temperature (T ₁ ). By continuing the forming process, the material is rapidly heated to a temperature at which it exhibits superplasticity due to the heat generated during processing, and when the temperature reaches the superplasticity manifestation temperature range, the machining ends and the mold temperature is lower than the superplasticity manifestation temperature. Therefore, it is rapidly cooled by contact heat transfer and cooled to a structurally stable temperature range.

Rapid heating, processing, and cooling are indispensable conditions for plastic working of materials such as amorphous alloys and fine crystalline materials in which the microstructure changes at a certain temperature. By adopting it, superplastic working of bulk material, solidification forming of powder material, and superplastic diffusion bonding become possible. Further, according to the method of the present invention, since heating, processing and cooling are performed in one step, the cycle time is shortened, solidification molding can be performed in a short time, and the time of exposure to high temperature is short, so molding processing is performed. Changes in the structure of the product (such as coarsening of crystal grains) and accompanying deterioration of physical properties are minimized. As a result, it is possible to manufacture a superplastic molded product without deteriorating the characteristics of the material.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described more specifically below with reference to the embodiments of the present invention with reference to the accompanying drawings.

FIG. 1 shows an essential part of an embodiment of an apparatus for producing a superplastic forming product according to the present invention.
In the figure, 1 is a mold, and the mold 1 is a material 7 (bulk material,
It has a supply part 2 to which a powder material) is supplied, a forming part 4 in which a material 7 is formed into a desired shape, and a passage part 3 which communicates between the supplying part 2 and the forming part 4. A heating unit 6 is provided on the side of the supply unit 2 of the mold 1. Further, a punch 5 having a cross-sectional shape corresponding to the hole of the supply unit 2 is arranged above the supply unit 2 so as to be slidable in the hole of the supply unit 2 so as to be vertically movable.

In the forming process, first, the superplastic material 7 is loaded into the supply part 2 of the mold 1, and the temperature rise (ΔT) from the temperature (T ₂ ) showing superplasticity due to the process heat generation.
The heating means 6 heats up to the heating temperature (T ₁ ) obtained by subtracting. When the heating temperature (T ₁ ) is reached, the punch 5 arranged immediately above the supply unit 2 pressurizes all at once. The raw material 7 is extruded to the molding portion 4 through the passage portion 3 and compressed, and is rapidly heated to a temperature range exhibiting superplasticity due to heat generation during processing. Subsequently, it is rapidly cooled due to the temperature difference between the molding unit 4 and the mold 1, and is molded and solidified into a desired shape. As the heating means, any conventionally known heating means such as induction heating, contact heating, and electric heating can be used. By performing the forming process by such a method, it is possible to heat with a small electric power as compared with the case of rapidly heating from room temperature to a predetermined temperature in the superplasticity developing temperature range. 2 in which material 7 and heating means 6 are arranged
Since it utilizes cooling by contact heat transfer with the low temperature of the molding part 4 itself which narrows and separates the passage part 3 from each other, it is economical, of course, and the time to be exposed to the high temperature is short, so that the structure change (crystal (Grain coarsening, etc.) and accompanying deterioration of physical properties are minimized, and plastic working can be reliably and easily performed without impairing the characteristics of the material.

The basic structure of the manufacturing apparatus shown in FIG. 2 is the same as that of FIG. 1, but in the apparatus of FIG. 1, the passage portion 3 and the molding portion 4 are located on the side of the supply portion 2. On the other hand, in the apparatus of FIG. 2, the passage portion 3a and the molding portion 4a of the mold 1a are located below the supply portion 2. When molding is performed using such a mode of the apparatus of FIG. 2, that is, an apparatus in which the direction in which the material is extruded is the same as the ascending / descending direction of the punch 5, a recess is likely to occur in the center of the bottom surface of the molded product. In order to prevent this, a cut-out molding portion 8 is provided at the center of the bottom surface of the molding portion 4. As a result, the central portion of the bottom surface of the molded product has a convex shape, but it is likewise cut after molding together with the convex portion formed in the passage portion.

As the material to which the manufacturing method of the present invention is applied, any material having a large deformability such as having superplasticity to be subjected to plastic working can be applied.
The following superplastic metal materials and rapidly solidified alloy powder solidifying materials described in No. 7178 can be advantageously used. The superplastic aluminum-based alloy described in JP-A-6-17178 is produced by quenching an alloy material having a specific composition to obtain an amorphous phase, a mixed phase of amorphous and fine crystalline, or a fine crystalline phase. It is obtained by preparing an aluminum-based alloy, which is heat-treated at a predetermined temperature for a predetermined period of time, and subjecting it to thermomechanical treatment to adjust the crystal grain size and the intermetallic compound grain size. Diameter 0.005 ~ 1μm
In the matrix of aluminum or a supersaturated solid solution of aluminum, an average particle consisting of a stable phase or a metastable phase of an intermetallic compound of the matrix element (A1) and other alloy elements or other alloy elements It is a superplastic aluminum-based alloy material in which particles having a size of 0.001 to 0.1 μm are uniformly dispersed, and its alloy system includes the following compositions.

(A) Al _a M ¹ _b X _e (where M ¹ : M
at least one element selected from n, Fe, Co, Ni and Mo, X: Nb, Hf, Ta, Y, Zr, Ti,
At least one element selected from rare earth elements and aggregates of rare earth elements (Mm; misch metal), a, b, e
Is in atomic percent 75 ≦ a ≦ 97, 0.5 ≦ b ≦ 1
5, a superplastic aluminum-based alloy material having a composition represented by 0.5 ≦ e ≦ 10), (B) Al _a M ¹ _(bc) M ² _c X
_e (provided that at least one element selected from M ¹ : Mn, Fe, Co, Ni and Mo, at least one element selected from M ² : V, Cr and W, X: Nb, H
At least one element selected from f, Ta, Y, Zr, Ti, a rare earth element and an aggregate of rare earth elements (Mm; misch metal), and a, b, c, and e are 7 in atomic percent.
5 ≦ a ≦ 97, 0.5 ≦ b ≦ 15, 0.1 ≦ c ≦ 5,
0.5 ≦ e ≦ 10), a superplastic aluminum-based alloy material having a composition represented by (C) Al _a M ¹ _(bd) M ³ _d X _e
(However, at least one element selected from M ¹ : Mn, Fe, Co, Ni and Mo, M ³ : Li, Ca, M
At least one element selected from g, Si, Cu and Zn, X: Nb, Hf, Ta, Y, Zr, Ti, a rare earth element and an aggregate of rare earth elements (Mm; misch metal).
At least one element selected from a, b, d, and e is in atomic percent 75 ≦ a ≦ 97, 0.5 ≦ b ≦ 15,
0.5 ≦ d ≦ 5, 0.5 ≦ e ≦ 10), a superplastic aluminum-based alloy material, and (D) Al
_a M ¹ _(bcd) M ² _c M ³ _d X _e (where M ¹ : Mn, F
At least one element selected from e, Co, Ni and Mo, at least one element selected from M ² : V, Cr and W, M ³ : Li, Ca, Mg, Si, Cu and Z
at least one element selected from n, X: Nb, H
At least one element selected from f, Ta, Y, Zr, Ti, a rare earth element and an aggregate of rare earth elements (Mm; misch metal), and a, b, c, d, and e are atomic percentages 75 ≦ a ≦ 97. , 0.5 ≦ b ≦ 15, 0.1 ≦ c ≦
5, 0.5 ≦ d ≦ 5, 0.5 ≦ e ≦ 10), a superplastic aluminum-based alloy material.

The alloy material having the above composition has excellent heat resistance, does not cause grain growth even at high temperatures, and can obtain fine crystal grains and intermetallic compounds after the thermomechanical treatment, and has high strength at high temperature. It has characteristics. Further, the alloy having the above composition is subjected to heat treatment and thermomechanical treatment (thermo-mechanical treatment).
tment: For example, rolling, extrusion, etc.), a superplastic material having a fine crystal structure in which smooth grain boundary movement or slippage occurs is obtained, which exhibits a large elongation at a relatively high strain rate. The superplastic aluminum-based alloy can also be produced by adjusting the raw material made of fine crystalline material having an average crystal grain size of 1 μm or less to the average crystal grain size and the average grain size of the intermetallic compound.
When molding is performed using the superplastic aluminum-based alloy as a raw material, the heating temperature at the time of molding is 350 to 600.
C., the strain rate is 10 ⁻² s ⁻¹ or more, preferably 10 ⁻¹ s ⁻¹ or more, and the flow stress at that time is about 20 to 17.
It is 0 MPa.

FIG. 3 shows Al ₈₈ Ni ₈ Mm _3.5 Zr _0.5.
FIG. 4 is a graph showing the relationship between strain rate and fracture elongation at various temperatures for a solidified material of rapidly solidified alloy powder having a composition of (atomic%), and FIG. 4 is a graph showing the relationship between strain rate and stress. The materials were prepared as follows. A1 ₈₈ N
An alloy having a composition of i ₈ Mm _3.5 Zr _0.5 (at%) was gas atomized to obtain a powder having a central particle size of 10 μm. These powders consisted of a fine A1 matrix phase and an intermetallic compound phase. The above powder was put into a metal capsule (made of copper) having an outer diameter of 50 mm (thickness of 1 mm) and heat-treated at 400 ° C. for 3 hours. Then 200
It was pressed at MPa to prepare an extrusion billet. Crystallization proceeded at this stage, and an A1 matrix phase having an average crystal grain size of 0.1 to 0.3 μm and an intermetallic compound phase of 0.05 μm or less were adjusted. This was extruded at an extrusion ratio of 10,360 ° C. to obtain an extruded rod. At this stage, the crystal grain size and the intermetallic compound grain size did not change from those of the extrusion billet. An induction coil was attached to the obtained extrusion rod, and the extrusion rod was heated by induction heating. The relationship between strain rate and elongation at break at various temperatures at this time is shown in FIG.
4 and the relationship between strain rate and stress at various temperatures is shown in FIG.

As is apparent from FIGS. 3 and 4, the aluminum alloy extruded material exhibits superplasticity at a high temperature of 673 K (400 ° C.) or higher, and has a strain rate of 10 ^-2 s ^-1 or higher, particularly 10 ^-1 〜.
It was found that a large elongation was exhibited in the range of 10 s ⁻¹ , and further, the higher the temperature was, the larger the elongation was, but the elongation tended to be reduced at a certain temperature or higher. Also, 600 ℃
It can be seen that an elongation of 600% can be obtained at a strain rate of (873 K) of 1 s ^-1 . When a material having superplasticity is heated and a forming process is carried out by utilizing the superplasticity phenomenon, the temperature range in which the material exhibits the superplasticity phenomenon, generally 75 to the melting point of the material
It is necessary to heat to a temperature of 95%, preferably 80 to 95%, optimally about 90%. In the strain rate-stress curve shown in FIG. 4, superplasticity is exhibited when m = 0.3 or more.

FIG. 5 is a graph showing the relationship between the temperature exposure time and the hardness and tensile strength of the aluminum alloy extruded material, and FIG. 6 is a graph showing the relationship between the temperature and the temperature exposure allowable time. As is clear from FIG. 5, hardness is closely related to tensile strength, and a nearly proportional relationship is seen. The horizontal straight line at the upper left of FIG. 5 indicates hardness and tensile strength at room temperature.
Further, from FIG. 6, for example, when exposed to a temperature of 550 ° C., the exposure time allowed for maintaining the tensile strength σ _B at 850 MPa is about 0.15 seconds or less, and the allowable exposure time for maintaining at 800 MPa. Approximately 1.2 seconds or less, 750M
It can be seen that it is 10 seconds or less for Pa and about 12 seconds or less for 700 MPa. That is, it can be seen from FIGS. 5 and 6 that when the required physical property values and the processing temperature are determined, the time allowed for that is regulated by itself.

Generally, the molding process is performed in a temperature range of 500 ° C. or higher. On the other hand, the permissible temperature exposure time for maintaining the required strength is the area on the left side of each curve in FIG. Therefore, the temperature at which processing can be performed while maintaining the required strength
The time region is the upper left region surrounded by the line of 500 ° C. in FIG. 6 and each curve of the required intensity. When heating to a temperature (T ₂ ) exhibiting superplasticity only by external heating in t seconds or less, the temperature rising rate is T ₂ / t at a minimum. On the other hand, according to the method of the present invention, the temperature (T
_The temperature obtained by subtracting the temperature rise (ΔT) due to heat generation from processing from ₂ ) is set as the heating temperature (T ₁ ), and this temperature (T ₁ ) is heated by the external heating means. Since this heating temperature (T ₁ ) is in a temperature range in which the material is structurally stable, the heating rate may be slower than in the above case, and the heating power capacity can be greatly reduced. By subsequently performing the forming process, it is rapidly heated to a temperature exhibiting superplasticity by the process heat, and when the process reaches the superplasticity expression temperature range, the processing is completed, and the mold temperature is lower than the superplasticity development temperature. It is rapidly cooled by contact heat transfer and cooled to a structurally stable temperature range.

Next, the Al ₈₈ Ni ₈ Mm _3.5 Zr _{0.5 is used.}
For the solidified material of the rapidly solidified alloy powder with the composition of φ8 mm
The initial heating temperature (T ₁ ) was set to 400 ° C. under the condition that the billet of FIG. 1 was compressed from the supply part 2 having the same inner diameter of the mold shown in FIG. The temperature rise due to the processing heat generated during the molding process performed in the above and the predicted value by calculation are shown below. First, when the temperature rise (ΔT) due to heat generated by processing is calculated, the m value in the above equation (1) is set to m = 0.3 from the data shown in FIG. Next, when the strain is calculated, the strain due to the reduction in cross section (extrusion ratio R = 10)
Is calculated as 3.23 and 1 from Equation (3) of Equation 3 below, and the shear strain due to the angle is calculated from Equation (4), and the total strain is 4.23.

(Equation 3)

On the other hand, if the initial heating temperature is set to 400 ° C., the K value in the above equation (1) is K = 20 at 400 ° C.
It is. Therefore, by substituting these values into the above equation (2) to obtain ΔT, ΔT = 331 ° C. as shown in the following formula 4.
It is calculated that the maximum temperature exceeds 600 ° C.

[Equation 4] However, the above calculation is performed by assuming that the K value at the initial heating temperature (extrusion start temperature) is constant, but in reality, the temperature rises due to the heat generated by processing, so the K value decreases (σ decreases), The amount of heat generated by processing decreases (K value at 600 ° C. is 1/10 of K value at 400 ° C. when K = 2). 400
It has been experimentally sought that the work amount corresponding to the heat generated by processing when the temperature rises from 0 ° C to 600 ° C is 1/2 of the work amount at the initial heating temperature. Therefore, the temperature rising from 400 ° C to 600 ° C is 331/2 ≒ 165
℃. Therefore, it is expected that the temperature will reach a maximum of 565 ° C. due to processing heat. On the other hand, after the billet (φ8 mm) was actually loaded into the material supply unit 2 of the mold 1 shown in FIG.
It was heated up to ℃ and subjected to pressure processing at an initial strain rate of 1S ^-1 with a punch 5 installed directly above the supply section.
The temperature rose to ℃ and was extruded into the molding section 4 to complete the molding. The temperature rise of 140 ° C. due to the heat generated by processing is slightly different from the calculated value, but in any case, the temperature reaches the superplasticity expression temperature range of the material, and the initial heating temperature is calculated from the value predicted by the calculation as described above. It can be seen that the molding process can be sufficiently performed even if is set.

[0023]

As described above, according to the method for producing a superplastic forming product of the present invention, the heat generated during processing is used to perform heating, processing and cooling in one die for forming. Since this is performed, the following effects and advantages can be obtained. (B) After the material is heated to a structurally stable temperature range by an external heating means, it is rapidly heated to a temperature at which it exhibits superplasticity due to processing heat during forming and reaches the superplasticity manifestation temperature range. At the end of processing, the temperature difference between the mold and the mold rapidly cools it to a structurally stable temperature range, which shortens the time it is exposed to high temperatures. (Coarsening, etc.) and accompanying deterioration of physical properties are minimized. As a result, it is possible to manufacture a superplastic molded product without deteriorating the characteristics of the material. (B) Since heating, processing, and cooling can be performed in one process in one mold, the processing cycle time is shortened, and because superplastic processing is performed at high speed, molding of complicated shapes and precision molded products can be performed. Molding can be performed in a short time. (C) Temperature (T ₂ ) at which superplasticity is achieved by utilizing heat generated during processing
Since the temperature is raised to 0, there is almost no extra heating, the thermal efficiency is extremely excellent, and the heating temperature (T ₁ )
Since the heating can be performed at a gradual heating rate, heating can be performed with a small amount of electric power as compared with the case of rapid heating, and the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an essential part of an example of an apparatus for performing the method of the present invention.

FIG. 2 is a cross-sectional view of a main part of another example of the apparatus for performing the method of the present invention.

FIG. 3 is a graph showing the relationship between strain rate and elongation at break at various temperatures for a rapidly solidified alloy powder solidified material having a composition of Al ₈₈ Ni ₈ Mm _3.5 Zr _0.5 (at%).

FIG. 4 is a graph showing the relationship between strain rate and stress at various temperatures of a rapidly solidified alloy powder solidified material having a composition of Al ₈₈ Ni ₈ Mm _3.5 Zr _0.5 (at%).

FIG. 5 is a graph showing the relationship between temperature exposure time and hardness and tensile strength of a rapidly solidified alloy powder solidified material having a composition of Al ₈₈ Ni ₈ Mm _3.5 Zr _0.5 (at%).

FIG. 6 is a graph showing the relationship between the temperature of the rapidly solidified alloy powder solidified material having a composition of Al ₈₈ Ni ₈ Mm _3.5 Zr _0.5 (at%) and the temperature exposure allowable time.

[Explanation of symbols]

1 mold, 2 supply section, 3 passage section, 4 molding section, 5
Punch, 6 heating means, 7 material, 8 excision molding part

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location C22K 3:00

Claims (3)

[Claims] 1. A supply section of a mold having a supply section for supplying a material, a molding section for molding the material into a desired shape, and a passage section communicating between the supply section and the molding section. A method for producing a superplastically formed product, in which a material that exhibits superplasticity is loaded, and the material is supplied to the forming part via the passage part and compressed to perform the forming process, and is added to the material of the supplying part. The heating temperature (T ₁ ) is the temperature at which the material exhibits superplasticity (T ₂ ).
And a temperature rise (ΔT) due to processing heat generated when the material is extruded from the supply part to the passage part and deformed, and a method for manufacturing a superplastically formed product. 2. The temperature rise (ΔT) due to heat generated by processing is calculated from the following equations (1) and (2), and the heating temperature (T
_The method for producing a superplastically formed product according to claim 1, wherein ₁ ) is set by T ₁ = T ₂ −ΔT. [Equation 1] 3. The method for producing a superplastically molded product according to claim 2, wherein the heating temperature (T ₁ ) is controlled to be lower than the crystal coarsening start temperature (T _X ) of the material exhibiting superplasticity.